Using the code autostructure, extensive calculations of inner-shell atomic data have been made for the chemical elements He, C, N, O, Ne, Na, Mg, Al,

We calculate the efficiency of iron K line emission and iron K absorption in photoionized models using a new set of atomic data. These data are more comprehensive than those previously applied to the modeling of iron K lines from photoionized gases and allow us to systematically examine the behavior of the properties of line emission and absorption as a function of the ionization parameter, density, and column density of model constant density clouds. We show that, for example, the net fluorescence yield for the highly charged ions is sensitive to the level population distribution produced by photoionization, and these yields are generally smaller than those predicted assuming the population is according to statistical weight. We demonstrate that the effects of the many strongly damped resonances below the K ionization thresholds conspire to smear the edge, thereby potentially affecting the astrophysical interpretation of absorption features in the 7-9 keV energy band. We show that the centroid of the ensemble of Kα lines, the Kβ energy, and the ratio of the Kα1 to Kα2 components are all diagnostics of the ionization parameter of our model slabs.

As part of the IRON Project, radiative rates have been calculated for the forbidden transitions within the ground configuration of atoms and ions in the carbon (2s2p) and oxygen (2s2p) isoelectronic sequences for . The atomic structure code superstructure was used, which allows for configuration interaction, relativistic effects and semi-empirical term energy corrections. Comparisons are made with previous theoretical datasets for the same sequences. It is shown once again that, to obtain reliable transition probabilities, in particular those of the electric quadrupole type, it is essential to use accurate and consistent experimental transition wavelengths. For the C and O sequences such data are fortunately available from the work of Edlén 1983, 1985. The general accuracy of the present probabilities is rated to be within 10%, with the exception of some electric quadrupole transitions in low-Z ions whose radiative rates are small with an accuracy not better than %.

Making use of the atomic structure computer program SUPERSTRUCTURE, radiative transition probabilities are calculated for the forbidden lines in the ground configuration $$1s^2 2s^2 2p^6 3s^2 3p^3$$ of all the members of the P I isoelectronic sequence up to Ni XIV. Elaborate procedures such as configuration interaction, relativistic corrections to the magnetic dipole operator, special radial wave functions and semi-empirical term energy corrections are used in the present calculation. This leads to considerable improvements over previous work. The importance of these changes is discussed in connection with some astrophysical problems.